As those skilled in the art are aware, infrared (IR) reflective additives severely degrade polycarbonate compositions resulting in drop in molecular weight and an increase in melt flow rate.
U.S. Pat. No. 5,153,068, issued to Kohara et al., describes a coated color particle with extremely low susceptibility to decoloring. The coated color particle comprises a colored core particle and a coating layer formed on the surface of the core particle, wherein the coating layer is formed by treatment of the core particle with an agent selected from the group consisting of silane compounds, silyl isocyanates, and organic titanium compounds.
Dardarts et al., in U.S. Pat. No. 5,256,728, provide pigmented polycarbonate compositions which are substantially stable with respect to molecular weight and melt viscosity and are prepared by blending a redistributed polycarbonate with titanium dioxide free from polysiloxane coatings.
U.S. Pat. No. 5,968,652, issued to Hanggi et al., discloses coated particles that are said to be well suited for use as absorption media in chromatographic processes. The coated particles comprise a substrate, such as aluminum, silicon, titanium or zirconium oxide particles, containing polymerized silane moieties on a surface of the substrate. The silane moieties include two or three olefinic groups as well as at least one useful ligand.
Gorny et al., in U.S. Pat. No. 6,841,240, describe a multilayered article made of a plastic material which exhibits high IR reflection and a high gloss. The article includes at least three layers A, B and C, wherein layer A contains a transparent thermoplastic plastics material, and wherein layer B contains a transparent thermoplastic plastics material and a pigment which consists of a transparent support material and a titanium dioxide layer of thickness 150 to 200 μm and where layer C contains a transparent thermoplastic plastics material.
U.S. Patent Application Publication No. 2003/0032755, in the name of Gorny et al. provides compositions containing a thermoplastic synthetic material and a multi-layered pigment, a method for producing products containing said compositions and to products containing the compositions, in particular, to panels containing said compositions.
A need continues to exist for polycarbonate composition containing infrared (IR) reflective additives which have improved melt flow properties.